The use of some electronic devices requires the identification of the user before the functions of the electronic device are activated. For example in mobile stations, such as GSM mobile stations and UMTS mobile stations, a so-called SIM card (Subscriber Identity Module) is used, which is placed in a connector set for this purpose in the mobile station. This SIM card is typically arranged in a card format, and it has the necessary connector pins for supplying the operating voltage to the SIM card as well as for transferring information between the SIM card and the mobile station. This SIM card contains stored user identification data, such as an international mobile subscriber identifier (IMSI), a personal identity number (PIN) and a personal unlocking key (PUK). Furthermore, the SIM card may contain a stored telephone number e.g. for addressing the debiting of calls to the correct user. Part of these identification data are stored in the memory means of the SIM card in such a way that the user cannot modify them. On the other hand, the personal identity number, i.e. the PIN code, is arranged to be changeable by the user. In mobile stations of prior art, this card containing the SIM card must be connected to the mobile station before the mobile station can be used for calls. In some cases, it is only possible to call emergency numbers without the SIM card. In addition that the SIM card is connected to the mobile station, the user must select his/her personal identity number with the keypad of the mobile station, after which the mobile station operates normally, presupposing that the PIN code was selected correctly.
In mobile stations of prior art, this connector for the SIM card is arranged inside the mobile station or in a separate reading device, wherein the SIM card is placed in this reading device and the reading device is connected via a cable to the mobile station. In such mobile stations in which the connector of the SIM card is arranged inside the mobile station, the connector is typically placed in such a way that the insertion and removal of the SIM card requires that the battery is removed from the mobile station. However, the user may have several mobile stations which he/she wishes to use even simultaneously. Consequently, the use of different mobile stations requires even the purchase of several SIM cards and simultaneously also the purchase of several mobile subscriptions, or the change of the SIM card to the mobile station which the user wishes to use each time. It is often not reasonable to purchase several SIM cards e.g. for the reason that the user must then pay maintenance and other costs for several mobile subscriptions. Moreover, it is also difficult to change the SIM card from one mobile station to another mobile station, because the mobile stations must then be closed and the battery must be removed before the SIM card can be removed from one mobile stations and be transferred to the other mobile station. Furthermore, this alternative does not make it possible to use the mobile stations simultaneously.
SIM cards presently in use are arranged to be such that they can be used either as cards of credit-card size or as cards with a considerably smaller size, approximately 1.5 cm2. In this case, also the SIM card connector of the mobile station is arranged to be suitable for connecting either a card of credit-card size or said smaller card. A problem with particularly the SIM card of credit-card size but also with the smaller SIM card is that it sets restrictions on reducing the size of the mobile station. On the other hand, it is a drawback with the smaller SIM card size that the handling of such a SIM card is difficult, and it may be easily lost.
One drawback in the external SIM card connection of prior art is that it requires the arrangement of a wiring between the SIM card reading device and the mobile station. Also this solution is not suitable in situations in which the user would like to use two or more mobile stations simultaneously. Furthermore, the user should in each mobile station have means for connecting an external SIM card reading device to the mobile station.